Among the variables that require consideration in the design and manufacturer of bowling shoes are individual bowling style, the left- or right-handedness of the bowler, the preferred relative amounts of slide and traction for each shoe of a pair, and the surface conditions of the bowler's shoes in relationship to the bowling lane. Accurate approach to the foul line and precise delivery of the ball generally require that the bowler have the ability to control the slide action and the traction action of each foot independently. Several attempts have been made to construct bowling shoes based on a standard shoe type with a separate raised heel and an arch elevated from the floor or lane surface. Selectable control of the sole surface to meet the individual bowler's preference then requires specific designs to the separate ball-of-the-sole and the heel regions. Often, manufacturers provide small inserts of varying coefficients of friction materials, so that the bowler must keep track of a confusing number of separate sole attachments. Current bowling shoes are constructed so that a single pair can fit only a left- or right-handed bowler. Although only a relatively small number of bowlers may be left-handed, to meet the needs of all potential customers, inventory must be maintained in all sizes for both left- and right-handed bowlers. This contributes to an unacceptable amount of waste and ultimately increases the cost of the shoe to the bowler.
Typically, a pair of bowling shoes may include a slide shoe and a traction shoe, determined by the bowler's left- or right-handedness. The sole surface of the slide shoe is generally selected for relative slide action with a sole at least partly comprised of a material with a lower coefficient of friction, for example, natural or synthetic leather or leather substitutes, including natural or synthetic suede or buckskin leather. The sole surface of the traction shoe is generally selected for good relative traction with a sole at least partly comprised of a material with a higher coefficient of friction, for example, natural or synthetic rubber or rubber substitutes.
McCord, U.S. Pat. No. 2,640,283, issued May 10, 1952, and McCord, U.S. Pat. No. 3,027,661, issued Apr. 3, 1962, each relate to a bowling shoe with a sole insert that extends generally along the ball of the foot. One insert may be exchanged for another, and each insert has a different coefficient of friction. The inserts shown in the '283 patent each have extending tangs which interfit with slots in the permanent sole area of the shoe. The inserts shown in the '661 patent attach by means of a hook-and-loop material. Note that the entire permanent area of the sole has a single coefficient of friction surface, and that each insert has a single coefficient of friction surface.
Cohen, U.S. Pat. No. 3,672,077, issued Jun. 27, 1972, is directed to a bowling shoe with removable cleats attached to apertures in the sole. Each of the cleats may have a single different coefficient of friction, so that by selecting specific cleats, it is said that the bowler may obtain the desired low or high traction characteristics for the sole. Note that the entire permanent area of the sole has a single coefficient of friction surface, and that each insert has a single coefficient of friction surface.
Taylor, U.S. Pat. No. 4,716,664, issued Jan. 5, 1988, describes a bowling shoe that has a specifically designed heel with different outer and inner bottom surfaces. The outer bottom heel surface has a relatively high coefficient of friction as compared to the inner heel surface. The shoe for the non-sliding foot has a sole with a higher coefficient of friction and a conventional uniform heel surface. Note that the individualization is only to the slide shoe and that the traction shoe is of a traditional style. According to Taylor, a single pair of shoes can only be designed for a right handed bowler or for a left handed bowler and only with a single type of slide action is provided to the slide shoe.
Famolare, U.S. Pat. No. 5,542,198, issued Aug. 6, 1996, relates to a bowling shoe, in which the shoe sole has a replaceable slide pad only on the tread surface of a shoe with a standard raised heel. The slide pad extends from the toe end of the shoe sole to about the arch portion and extends across the width of the tread surface. The removable slide pad that has a peripheral margin about equal to the peripheral margin of the slide area on the tread surface. The heel also has separate selectively replaceable heels, to provide a different desired coefficient of friction to the heel. Note that each insert (to the ball region or the heel region) has only a single coefficient of friction surface. Note also that the replaceable portion of the sole is only provided on the slide shoe. No selectability is provided for the traction shoe, nor does Famolare allow for changing the left- or right-handedness of a pair of shoes by interchanging the replaceable slide area.
These and other bowling shoe constructions have been proposed and are currently available. None of them provide all of the advantages of the present invention, including, among other features described herein, selectability of amounts of regions of different coefficients of friction of the sole surface. None of these prior bowling shoes offer a wedge-soled shoe with selectable areas of slide or traction over the entire sole surface. None of these prior bowling shoe arrangements have the ability to designate either shoe to be the "slide" shoe or the "traction" shoe simply by applying a selected replaceable sole member to the shoe, thus changing the left-/right-handedness of the pair of shoes.